Various sensors can be used to detect and characterize materials, such as biological, chemical, and/or radiological materials. For example, nanopore or nanochannel sensors have been developed to detects and characterize biological materials. In recent years, nanopore based sequencing approaches for detecting and characterizing biological materials have gained interest because such techniques offer two distinct advantages over other technology platforms, including: (i) point transduction capability and (ii) high speed nanopore translocation. Methods of nanopore based sequencing of biological material include: ion current blockade technique and more recently, transverse electron transport techniques. While these techniques hold promise to deliver a solution that is able to read-out the three billion base pairs at low cost and in a reasonably short period of time, they suffer from few fundamental limitations.
Ion current blockade techniques are limited by relatively low ion mobility in aqueous solution, when measuring ion-current across a nanopore. A recent study shows a current response over a time period of 104 micro seconds for a step input applied and measured across a nanopore device, potentially limiting the rate of sequencing to below 1000 bases per second. Transverse electron transport measurements on the other hand are limited in sequencing-speed by quantum mechanical noise. In both ion current blockade and transverse electron transport techniques, these limitations result in failure to exploit the most significant advantage of high-speed DNA translocation in nanopore. Researchers have thus used methods to slow-down the DNA, from its natural high speed translocation of few million bases per second in solid state nanopores and up to 100 million bases per second in graphene nanopores.
A low cost, high quality solution to whole genome sequencing is generally desirable. Such a technology at low cost could lead to true personalized diagnostics and personalized therapeutics. Various technologies aim to provide just such a solution utilizing various technology approaches. However, such systems are generally expensive and therefore out of reach for many patients. Accordingly, a device and method where the total cost, cumulative of devices, instrumentation, reagents, time-cost and other resources, is relatively low, i.e., a desktop sequencer that will enable monitoring of mutations in a tumor over a period of time, and avails genome sequencing even to poorer countries, are desired.